Color imaging using a monochromatic digital camera

Patent metadata

Field	Value
Publication number	US-2016156891-A1
Application number	US-201414905811-A
Country	US
Kind code	A1
Filing date	Jul 31, 2014
Priority date	Aug 3, 2013
Publication date	Jun 2, 2016
Grant date	—

Abstract

Monochromatic cameras and methods for using such cameras to obtain a still or video color image of an object or scene. The image sensor of such cameras is clear, without a color filter array. A diffused-dispersed and optionally randomized image of the object or scene obtained at the image sensor is processed directly into a number R<K of spectral images in R wavebands. K−R spectral images are interpolated from the R spectral images. A color image is then reconstructed using the directly processed R spectral images and the K−R interpolated spectral images. The interpolated images may exemplarily be obtained using a spline subdivision algorithm.

First claim

1 . A method for obtaining a color image of an object or scene using a camera having a pixelated clear image sensor without color filters, the method comprising the steps of:
a) obtaining a diffused-dispersed (DD) image at the image sensor in a snapshot; b) processing the DD image to obtain K spectral images in K spectral bands where K≧3; and c) reconstructing a color image from the K spectral images.

2 . The method of claim 1 , wherein the step of obtaining a DD image includes obtaining a diffused-dispersed and randomized (DDR) image.

3 . The method of claim 1 , wherein the step of processing the DD image includes processing the DD image to provide R<K spectral images in R wavebands and using the R images to obtain K−R interpolated images, and wherein the step of reconstructing a color image from the K spectral images includes reconstructing a color image using the R spectral images and the K−R interpolated spectral images.

4 . The method of claim 2 , wherein the step of processing the DDR image includes processing the DDR image to provide R<K spectral images in R wavebands and using the R images to obtain K−R interpolated images, and wherein the step of reconstructing a color image from the K spectral images includes reconstructing a color image using the R spectral images and the K−R interpolated spectral images.

5 . The method of claim 3 , wherein the interpolated images are obtained using a spline subdivision algorithm.

6 . The method of claim 5 , wherein the spline subdivision algorithm is a binary spline subdivision algorithm.

7 . The method of claim 5 , wherein each spectral image includes a set X×Y of multipixels, each multipixel including K wavebands, and wherein the interpolation is performed simultaneously on the entire multipixel set.

8 . The method of claim 6 , wherein each spectral image includes a set X×Y of multipixels, each multipixel including K wavebands, and wherein the interpolation is performed simultaneously on the entire multipixel set.

9 . The method of claim 1 , wherein the step of reconstructing a color image from the K spectral images includes reconstructing a still color image.

10 . The method of claim 1 , wherein the step of reconstructing a color image from the K spectral images includes reconstructing a video color image or color frame.

11 . A camera for obtaining a color image of an object or scene, comprising:
a) a lens; b) a pixelated clear image sensor without color filters; c) diffuser means to obtain in a snapshot a diffused-dispersed (DD) image at the image sensor; and d) a processor configured to process the DD image into K spectral images in K spectral bands where K≧3, and to reconstruct a color image from the K spectral images.

12 . The camera of claim 11 , wherein the diffuser means include a restricted isometry property (RIP) diffuser.

13 . The camera of claim 12 , further comprising a randomizer used in conjunction with the diffuser means to provide a diffused-dispersed and randomized (DDR) image at the image sensor and wherein the processor is further configured to process the DDR image into K spectral images in K spectral bands where K≧3, and to reconstruct a color image from the K spectral images.

14 . The camera of claim 12 , wherein the processor is further configured to process the DD image to obtain directly R<K spectral images in R wavebands, to interpolate from the R spectral images K−R interpolated spectral images and to reconstruct the color image using the directly processed R spectral images and the K−R interpolated spectral images.

15 . The camera of claim 13 , wherein the processor is further configured to process the DDR image to obtain directly R<K spectral images in R wavebands, to interpolate from the R spectral images K−R interpolated spectral images and to reconstruct the color image using the directly processed R spectral images and the K−R interpolated spectral images.

16 . The camera of claim 13 , wherein the randomizer is a hardware randomizer.

17 . The camera of claim 13 , wherein the randomizer is implemented in software.

18 . The camera of claim 14 , wherein the processor configuration to interpolate from the R spectral images K−R interpolated spectral images includes a configuration to obtain the K−R spectral images using a spline subdivision algorithm.

19 . The camera of claim 18 , wherein the spline subdivision algorithm is a binary spline subdivision algorithm.

20 . The camera of claim 15 , wherein the processor configuration to interpolate from the R spectral images K−R interpolated spectral images includes a configuration to obtain the K−R spectral images using a spline subdivision algorithm.

21 . The camera of claim 20 , wherein the spline subdivision algorithm is a binary spline subdivision algorithm.

22 . The camera of claim 11 , wherein the color image is a still color image.

23 . The camera of claim 11 , wherein the color image is a video color image or color frame.

Assignees

• Univ Ramot
• Univ Ramot

Inventors

• Averbuch Amir
• Golub Michael
• Nathan Menachem
• Malinsky Roman
• Zheludev Valery

Classifications

• H04N23/843

  Demosaicing, e.g. interpolating colour pixel values · CPC title

• G01J3/28 Primary

  Investigating the spectrum (using colour filters G01J3/51) · CPC title

• H04N9/045

  Electricity · mapped topic

• H04N9/43 Primary

  Conversion of monochrome picture signals to colour picture signals for colour picture display · CPC title

• G02B5/201

  in the form of arrays · CPC title